Horton

Re: Unhappy about API changes in the no-fsm-for-small-rels patch

Amit Kapila <amit.kapila16@gmail.com>

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From: Amit Kapila <amit.kapila16@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andres Freund <andres@anarazel.de>, John Naylor <john.naylor@2ndquadrant.com>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2019-04-18T06:48:41Z
Lists: pgsql-hackers 
On Wed, Apr 17, 2019 at 9:50 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Andres Freund <andres@anarazel.de> writes:
> > On 2019-04-17 15:49:29 +0530, Amit Kapila wrote:
> >> OTOH, if we want to extend it later for whatever reason to a relation
> >> level cache, it shouldn't be that difficult as the implementation is
> >> mostly contained in freespace.c (fsm* functions) and I think the
> >> relation is accessible in most places.  We might need to rip out some
> >> calls to clearlocalmap.
>
> > But it really isn't contained to freespace.c. That's my primary
> > concern. You added new parameters (undocumented ones!),
> > FSMClearLocalMap() needs to be called by callers and xlog, etc.
>
> Given where we are in the release cycle, and the major architectural
> concerns that have been raised about this patch, should we just
> revert it and try again in v13, rather than trying to fix it under
> time pressure?
>

I respect and will follow whatever will be the consensus after
discussion.  However, I request you to wait for some time to let the
discussion conclude.  If we can't get to an
agreement or one of John or me can't implement what is decided, then
we can anyway revert it.

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

Commits

  1. Revert "Avoid the creation of the free space map for small heap relations".

  2. Improve code comments in b0eaa4c51b.

  3. During pg_upgrade, conditionally skip transfer of FSMs.

  4. Add more tests for FSM.

  5. Fix typos in commit 8586bf7ed8.

  6. tableam: introduce table AM infrastructure.

  7. Clear the local map when not used.

  8. Doc: Update the documentation for FSM behavior for small tables.

  9. Make FSM test portable.

  10. Avoid creation of the free space map for small heap relations, take 2.